Package and method of making

ABSTRACT

A rectangular blank for forming a tray having a strip of adhesive along each of two parallel edges and a score line in said blank parallel to each edge, the score lines intersecting to form a rectangle. Four slits are cut in said blank, each extending from an edge to one of the four intersections of the rectangle formed by the fold lines. A package comprising a tray having four vertical sides and a bottom, contents in said tray and a shroud extending over the contents. The shroud comprising a tube which may be closed at one end and extending down over the sides of the tray with the lower end of the shroud being bonded to adhesive material on the sides of the tray. The method of forming the tray. The method of forming the package.

United States Patent [54] PACKAGE AND METHOD OF MAKlNG 2 Claims, 8 Drawing Figs.

[52] [1.5. Cl 206/65, 53/30, 53/184, 206/4533 [S 1] Int. Cl ..B65b53/00, 865d 71/00, B65d 85/62 [50] Field of Search 206/65 S,

65 B, 65, 83.5, DIG. l8, 45.33; 229/32, 30, DIG. 12,43,53/30, I84

[56] References Cited UNITED STATES PATENTS 3,140,037 7/1964 Baum etal 3,410,396 11/1968 Copping 206/65 5 3,469,761 9/1969 Howell 229/32 FOREIGN PATENTS 691,904 8/1964 Canada 229/SC 1,467,274 12/1966 France 206/65 B Primary ExaminerWilliam T. Dixson, Jr. At!0rneys.l. Hughes Powell and Robert W. Wilson ABSTRACT: A rectangular blank for forming a tray having a strip of adhesive along each of two parallel edges and a score line in said blank parallel to each edge, the score lines inter secting to form a rectangle. Four slits are cut in said blank, each extending from an edge to one of the four intersections of the rectangle formed by the fold lines.

A package comprising a tray having four vertical sides and a bottom, contents in said tray and a shroud extending over the contents. The shroud comprising a tube which may be closed at one end and extending down over the sides of the tray with the lower end of the shroud being bonded to adhesive material on the sides of the tray.

The method of forming the tray.

The method of forming the package.

PATENTEU JUN29 mm SHEET 1 OF 3 ATTORNEY.

EDWARD M. BEGNAUD HARRY K. HUBENTHAL ATTORNEY.

PATENIED M29 ism SHEET 3 [1F 3 I FIG.6

VACUUM FIG] INVENTORS EDWARD M. BEGNAUD HARRY K. HUBENTHAL 7 W ATTORNEY.

PACKAGE AND METHOD OF MAKING BACKGROUND OF THE INVENTION Many products are shipped by rail or truck to retail outlets or subsequent manufacturing plants in rectangular corrugated paperboard containers or other foldable material, whereby the retailer or subsequent manufacturer must remove the products and destroy the container. For example, bales of rubber, individually packaged grocery items, canned goods, etc., are normally shipped in such rectangular corrugated paperboard containers.

There is a need in the industry for transparent containers so the contents many he observed without unpacking and for inexpensive containers which are of light weight and which firmly hold the products against displacement and which leave only a small fraction of material as trash.

BRIEF DESCRIPTION OF THE INVENTION This invention is an advancement in the art and is universally usable for both small and large packages. It includes a rectangular tray having a bottom and four sides folded upward and with overlapping flaps on each end of two parallel sides. The flaps are folded to extend around the comers of the tray to provide greater strength and smoother corners. When folded in place the flaps extend only partially across the width of the tray and the space between their ends provides an air passage. The product to be packaged is deposited on the tray and a tubular shroud is slipped downward to envelop the product and overlap the upwardly extending sides of the tray. The sides having the integral flaps include an adhesive strip on their outer surface which serves to bond the shroud to the tray. The shroud is heat shrunk about the product after it is bonded to the tray and the air within the shroud is withdrawn during the shrinking through the air passages located between the ends of the flaps.

It is an object of this invention to provide a blank for forming a tray which is foldable to form a bottom with upwardly extending sides and has a discontinuous strip of adhesive around the external surface of the sides.

It is a further object of this invention to provide a method of forming a tray having a discontinuous strip of adhesive around upwardly extending sidewalls of the tray.

It is a further object of this invention to provide a package including a tray with upwardly extending sidewalls, the contents to be packaged resting on said tray and a shroud extending over the contents and bonded to the tray.

It is a further object of this invention to provide a method of making a package which includes forming a tray, depositing the contents to be packaged on the tray and enclosing the contents in a heat shrinkable shroud and bonding the shroud to the tray.

Further objects of this invention will become obvious from a reading of the description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a plan view of a tray blank;

FIG. 2 is a perspective view of the tray formed from the blank of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a perspective view of the tray with a product in the tray showing the preferred embodiment of the shroud in place before shrinking;

FIG. 5 is a schematic view of the assembling, aligning, shrinking, cooling and weighing apparatus;

FIG. 6 is an elevational view of the shrinking apparatus and package taken along line 6-6 of FIG. 5;

FIG. 7 is a perspective view of the completed package; and

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7.

PREFERRED EMBODIMENT The preferred embodiment of this invention will be described with reference to the packaging of bales of rubber each weighing from about 25l00 pounds and indicated generally at 8. As will become obvious from a detailed reading of the description of this invention, many other items of commerce may be packaged in the same manner.

For convenience the package indicated generally at 10 will be described by the method making it. The initial step in the operation is to provide a blank 12 for forming a tray 14. This is preferably accomplished by providing a continuous length of corrugated paperboard product or other foldable material on which is deposited two continuous strips of adhesive 16, parallel to the sides of the length of tray material. Preferably, the adhesive 16 is deposited as a liquid but a preformed strip might be used. The thickness of the adhesive 16 shown in FIG. 3 is greatly exaggerated, a very thin coating is adequate. In a preferred embodiment the adhesive material is polyethylene.

In the preferred embodiment the length of material is then severed into lengths of predetermined size such as shown in FIG. 1. However, it is obvious that the severing of the blank into predetermined sizes could be accomplished prior to the deposition of the adhesive material 16 if desired.

Fold lines 17, 18, I9 and 20 are formed in the blank 12 parallel to the edges by usual and well known means. Usually this step is performed after the adhesive 16 is deposited. A relatively small amount of adhesive is required. The width of the strip is less than the height of the sides of the folded tray and is deposited between the fold lines 17 and 19 and the edges of the blank 12. In a typical application, an adhesive width of from 3-6 inches would be employed with a wall height of 7 inches.

Four slits 22 are cut in the blank 12 extending from an edge to the corners 23 formed by the fold lines 1720. In the preferred embodiment the slits 22 are made parallel with the strips of adhesive 16. However, it is obvious that they could be cut on a diagonal. The orientation of the slits 22 in the preferred embodiment is simply the most economical procedure. The straight cuts 22 allow for a minimum of folding steps. Where diagonal cuts are made an additional fold must be made on any extending flap of the sides 24.

As may be seen in FIG. '2, the folding of the sides 26 of the tray will leave a flap 28 on each end, integral with the sides 26, and which extends beyond the edge of the enclosure of the tray. These flaps 28 include the continuous extension of the strips of adhesive 16 and each flap is intended to be folded around the corner of the tray into parallel and overlying relationship with the sides 24, see FIG. 2. A space 30 between the edges of the flaps 28 serves as a channel for passage of air, as will be explained subsequently.

After the folding of the blank 12 to form the tray 14, the bales of rubber 8 are deposited therein. A conveyor belt or assembly line 32 supports the loaded tray 14 as a shroud 34 is pulled into place over the bales 8, see FIGS. 4 and 5. The shroud 34 comprises a tube of heat shrinkable material which may be closed at one end as shown in FIGS. 4 and 5 and is comprised of material which is substantially the same or compatible with the composition of the adhesive 16. For example, polyethylene, polypropylene, polyvinylchloride or any other suitable heat shrinkable thermoplastic material may be used. Polyethylene is the preferred material.

The shroud 34 is closed at one end in the preferred embodiv ment. However, because of the subsequently described shrinking, the upper end may be left open in some applications without detrimental results.

After the shroud 34 is pulled into place, the tray is moved along the assembly line 32 and aligned by vertical rollers 35 until it is in place to be exposed to a heat source such as a heating ring. In the preferred embodiment, the heating source 36 is rectangular to conform to the shape of the tray 14 and one side 38 may be adjustable (not shown) to accommodate various sizes of rectangular packages. A duct 40 conducts hot air from a source (not shown) to the heating ring 36 which has a plurality of apertures 42 directed toward the center of the ring for projecting the hot air against the surface of the package 10. Controls for the heat shrinking apparatus are shown generally at 43. Other structure may be used to direct heat against the shroud 34, i.e., a heating tunnel, hot air gun, etc., if desired.

The lower end of the shroud 34 extends down over the sides 24, 26 of the tray 14 and into contact with the strips of adhesive 16. In the preferred embodiment the heat source 36 is lowered to approximately the level of the bottom of the tray 14, at that time the heated air is released to impinge against the shroud 34. The lower edge of the shroud being heat shrinkable will thus tightly encompass the sides 24 and 26 of the tray 14 and the thermoplastic adhesive l6 will be softened and bond the shroud 34 to the tray. The shroud will not bond to the side 24 where no adhesive 16 extends, thereby leaving passages or channels 30. The heat source 36 will then move upward while still directing hot air against the shroud 34 and the shroud will continue to shrink and be pulled into tight engagement with the packaged material 8 until the heat source 36 rises to an elevations above the top of the package 10.

As is obvious, any air trapped within the shroud 34 could prevent an effective shrinking into close contact with the rubber bales 8. Thus, the side channels or passages 30 between the edges of the flaps 28 serve to conduct the air out of the shroud 34 as it shrinks. Probes may be inserted into the passages 30 to keep them open while the heating and shrinking is being conducted. However, such a precaution is usually unnecessary because the heated air within the shroud 34 is usually of a higher pressure than the external air, thus, it will automatically open the passages 30 without any such probe. It will also be noted that as the shroud shrinks, it will expel air from the package. A vacuum pump 41 may be provided to withdraw air from the shroud.

Because of the encompassing aspect of the shroud 34 and the bottom bond at 16, the direction of the shrinking is largely immaterial. Shrinking in any direction will tend to draw it into tight contact with the material encompassed. Because the orientation or direction of shrink potential is not critical, less expensive shroud material may be used.

It should be noted that this method and the resulting package are achieved with a minimum of packaging apparatus because the adhesive strip 16 around the folded tray 14 is discontinuous, thereby easily permitting fluid communication with the interior. That is, the flaps 28 are not overlapping and the resulting passage 30 allows the trapped air to escape or be withdrawn. Evacuating the air from the shroud 34 as it is being shrunk has been accomplished by the prior art primarily by providing a porous support for the material to be packaged. In prior art practices, the support is ordinarily made porous by puncturing the solid surface or by providing a support which is inherently porous, for example, sheets of compressed plastic granules. The puncture marks permit entry of contaminants and inherently weaken the base supporting the product and the inherently porous bases are usually weaker than any solid base. Thus, when the instant invention is used, a stronger, relatively impermeable base is the result, which allows a greater load to be placed on each tray and substantially excludes foreign matter.

The fact that the flaps 28 extend around the comers of the tray provides a continuous extension of one side and a resulting strengthening of the corner areas. In addition, the fact that the flaps are made integral with the side 26 which includes the continuous strip of adhesive 16, results in a better bond around the corners for the shroud 34.

Also, the secure bonding of the shroud to nearly the entire periphery of the load bearing tray contributes to the structural integrity of the package unit.

After the heat source 36 rises above the top of the package, the tray 16 is moved along the assembly line 32 to a cooling area 44 and then to a scale 46 for weighing. The package is then ready for storage or shipping. I

For ease of description the principles of the invention have been set forth in connection with but a single illustrated embodiment. It is not intended that the illustrated embodiment nor the terminology employed in describing it be limiting inasmuch as variations may be made by one having ordinary skill in the art without departing from the scope and spirit of the invention. Rather, it is intended that any restriction on the invention be limited to the spirit and scope of the appended claims.

We claim:

1. A package comprising a bottom tray, material on said tray, and a shrink-fit shroud of plastic material completely enclosing said material and overlapping said tray, said tray having the structure formed by scoring a flat rectangular blank of foldable material in continuous lines parallel with each side thereof, depositing a continuous layer of adhesive on two opposed sides only of said blank in the area defined by the scoring lines and the outer edges, forming four symmetrically positioned slits in said blank extending from corresponding points on the periphery of the blank parallel with the strip of adhesive to the four corners formed by the intersection of the said scoring lines, and the tray being folded along the said scoring lines to form upstanding walls two of which have a continuous adhesive coating and overlapping and folding the material in the region of said slits to form adhesively coated flaps which define, with said shroud, an adhesive-free air channel in the other two of said walls.

2. In a method for shrink-packing material held in a bottom tray employing a shroud of heat shrinkable plastic completely enclosing said material and overlapping said tray, the im provement which comprises employing as said tray a rectangular box with upstanding walls only two of which have overlapping side flaps defining, with said shroud, air channels, said walls being coated with adhesive except in the area of said channels, securing said shroud to said adhesive, and applying heat to the shroud to shrink same by means of a ring circumscribing said shroud starting in the region of said tray and moving said means upwardly over the said shroud while allowing air to escape through said channels. 

1. A package comprising a bottom tray, material on said tray, and a shrink-fit shroud of plastic material completely enclosing said material and overlapping said tray, said tray having the structure formed by scoring a flat rectangular blank of foldable material in continuous lines parallel with each side thereof, depositing a continuous layer of adhesive on two opposed sides only of said blank in the area defined by the scoring lines and the outer edges, forming four symmetrically positioned slits in said blank extending from corresponding points on the periphery of the blank parallel with the strip of adhesive to the four corners formed by the intersection of the said scoring lines, and the tray being folded along the said scoring lines to form upstanding walls two of which have a continuous adhesive coating and overlapping and folding the material in the region of said slits to form adhesively coated flaps which define, with said shroud, an adhesive-free air channel in the other two of said walls.
 2. In a method for shrink-packing material held in a bottom tray employing a shroud of heat shrinkable plastic completely enclosing said material and overlapping said tray, the improvement which comprises employing as said tray a rectangular box with upstanding walls only two of which have overlapping side flaps defining, with said shroud, air channels, said walls being coated with adhesive except in the area of said channels, securing said shroud to said adhesive, and applying heat to the shroud to shrink same by means of a ring circumscribing said shroud starting in the region of said tray and moving said means upwardly over the said shroud while allowing air to escape through said channels. 